Another good lesson can be found here

https://www.guitartricks.com/lesson.php?input=24936&s_id=2063

I can use a tuner to check string bends, using a Polytune 3, but it's awkward and, to be honest, I can't really see the point.

Develope your hearing at the same time as the technique itself; I honestly think that would be a better way to practice instead of trying to rely on a tuner to guage accuracy.